Prior to this invention, particularly in the field of dentistry where the dental mirror is an important instrument and requires unimpaired reflective surfaces, and also where such dental mirrors are very costly especially for the high quality front-coated mirrors, a major problem of scratching of the reflective surface has existed as incurred during sterilization and storage periods. Typical sterilization methods include dry heat in an oven at about 450 degrees Fahrenheit, and moist heat in an autoclave at about 253 degrees Fahrenheit, and cold sterilization in for example a solution of zephiran chloride or the like, and dry gas sterilization by poisonous gas such as ethylene oxide. In any one or more of these procedures of sterilization, dental instruments are generally placed into a tray or other container together, and it is the other instruments that accidentally strike and scar or scratch the dental mirror's reflective surface. While normally no one scratch is severe enough to fully thwart further use of the dental mirror, repeated scratches during the frequent and repeated sterilizations soon make use of mirror difficult, and eventually too poor for further use.
Heretofore there has been no available protective case or other practical way of protecting such dental mirrors that in normal procedures must be frequently sterilized as above-noted. A conventional cover or casing could itself touch and scratch the mirror surface. Also such casing, if any would have to be able to withstand the various conditions above-noted during such sterilizations. Any such case or protector would have little utility if it could not be utilized with conventional dental mirrors and without interfering with the normal utility of such dental mirrors; that is to say that such case or protector can not be a part integrally of the mirror, because as such the dental mirror could no longer be used for unimpaired movement within the limited spaces of the mouth. Likewise, such casing cannot be bulky and cumbersome, and should be easily but sturdily mountable and dismountable from the dental mirror.
U.S. Pat. No. 1,540,409 discloses solely a double vision mirror that can be opened and closed on the interconnecting hinge mounting one on the other. There is no mechanism for detaching one from the other and one is not intended to function without the other. The U.S. Pat. No. 2,434,311 discloses a semicircular member utilized to facilitate the moving of a filing into place within the mouth of a patient. While such do not relate to problems to which the present invention is directed, these patents represent the sole patents found in a novelty search.